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Home >> Saab >> 1993 >> 900 Base, 2D Convertible, Standard >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls - System/Component Tests >> Emission Systems & Sub-Systems >> Exhaust Gas RECIRCULATION (Except 9000 Series Turbo)

Exhaust Gas RECIRCULATION (Except 9000 Series Turbo)

  1. Remove connector plug from EGR modulator valve (located in engine compartment near left wheelwell). Connect jumper wire to pin No. 2 of EGR modulator valve and 12-volt power supply. Connect jumper wire to pin No. 1 of EGR modulator valve. Connect jumper wire briefly to ground and listen for click from modulator valve. If there is no sound, go to next step.
  2. Turn ignition off. Unplug connector from modulator valve. Measure resistance between modulator valve terminals. If resistance is not approximately 30 ohms, replace valve.
  3. Turn ignition on. Check for battery voltage at Green/White wire on modulator valve harness connector. If battery voltage does not exist, repair Green/White and/or Blue/Red wires to pin No. 87 of fuel pump relay. See Figure .
  4. With ignition off, unplug fuel injection ECM. Check White and Yellow/White wires between modulator valve harness connector and ECM for open or short circuit. If valve and wiring are okay, temporarily substitute known good fuel injection ECM. Retest system.
  5. Reconnect wiring to modulator valve and fuel injection ECM. Locate EGR temperature sensor. Temperature sensor is integral with EGR valve, located on intake manifold. Unplug connector from EGR temperature sensor.
  6. Start engine. With engine idling, measure resistance between EGR sensor terminals. Resistance should be several megohms. Apply vacuum to valve by connecting vacuum pump to Red-marked hose. Sensor resistance should drop to several thousand ohms. Replace EGR valve if resistance is not as specified.
  7. With ignition off, unplug fuel injection ECM connector. Check Yellow/White wire (between EGR temperature sensor and fuel injector ECM terminal No. 23) for open or short to ground. Check Black wire between temperature sensor and ground.
  8. If fault persists, disconnect Red-marked hose from modulator valve. Apply vacuum to hose. If engine RPM drops, EGR valve is okay. If engine RPM does not drop, check hoses, connections, and vacuum tank.
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